| 摘要 |
<p>PURPOSE:To reduce the probability of generation of malfunction at the time of runaway by monitoring the runaway of software by two decoders. CONSTITUTION:An address is supplied from a microcomputer (MPU) to the address decoders 1, 2 through an address bus. The output of the decoder 1 is connected to the input of a monostable multivibrator 3. A Q-output of the monostable multivibrator 3 is applied to one input of a NAND circuit 5 and the output of the address decoder 2 is supplied to the other input of the NAND circuit 5. The output of the NAND circuit 5 is supplied to the input of a monostable multivibrator 4 and the Q-output of the monostable multivibrator reduced to a signal indicating the generation of an alarm in a watchdog timer circuit.</p> |
